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Depending on an experimental approach to find optimal parameters for producing fully dense (relative density > 99%) Inconel 718 (IN718) components in the selective laser melting (SLM) process is expensive and offers no guarantee of success. Accordingly, this study aims to propose a multi-scale simulation framework to guide the choice of processing parameters in a more pragmatic manner.

In the proposed approach, a powder layer, ray tracing and heat transfer simulation models are used to calculate the melt pool dimensions and evaporation volume corresponding to a small number of laser power and scanning speed conditions within the input design space. A layer-heating model is then used to determine the inter-layer idle time required to maximize the temperature convergence rate of the solidified layer beneath the power bed. The simulation results are used to train surrogate models to construct SLM process maps for 3,600 pairs of the laser power and scanning speed within the input design space given three different values of the underlying solidified layer temperature (i.e., 353 K, 673 K and 873 K). The ideal selection of laser power and scanning speed of each process map is chosen based on four quality-related criteria listed as follows: without the appearance of key-hole melting; an evaporation volume less than the volume of the d90 powder particles; ensuring the stability of single scan tracks; and avoiding a weak contact between the melt pool and substrate. Finally, the optimal laser power and scanning speed parameters for the SLM process are determined by superimposing the optimal regions of the individual process maps.

The feasibility of the proposed approach is demonstrated by fabricating IN718 test specimens using the optimal processing conditions identified by the simulation framework. It is shown that the maximum density of the fabricated parts is 99.94%, while the average density is 99.88% and the standard deviation is less than 0.05%.

The present study proposed a multi-scale simulation model which can efficiently predict the optimal processing conditions for producing fully dense components in the SLM process. If the geometry of the three-dimensional printed part is changed or the machine and powder material is altered, users can use the proposed method for predicting the processing conditions that can produce the high-density part.

The purpose of this paper is to implement a closed loop regulated bidirectional DC to DC converter for an application in the electric power system of more electric aircraft. To provide a consistent power supply to all of the electronic loads in an aircraft at the desired voltage level, good efficiency and desired transient and steady-state response, a smart and affordable DC to DC converter architecture in closed loop mode is being designed and implemented.

The aircraft electric power system (EPS) uses a bidirectional half-bridge DC to DC converter to facilitate the electric power flow from the primary power source – an AC generator installed on the aircraft engine’s shaft – to the load as well as from the secondary power source – a lithium ion battery – to the load. Rechargeable lithium ion batteries are used because they allow the primary power source to continue recharging them whenever the aircraft engine is running smoothly and because, in the event that the aircraft engine becomes overloaded during takeoff or turbulence, the charged secondary power source can step in and supply the load.

A novel nonsingular terminal sliding mode voltage controller based on exponential reaching law is used to keep the load voltage constant under any of the aforementioned circumstances, and its performance is contrasted with a tuned PI controller on the basis of their respective transient and steady-state responses. The former gives a faster and better transient and steady-state response as compared to the latter.

This research gives a novel control scheme for incorporating an auxiliary power source, i.e. rechargeable battery, in more electric aircraft EPS. The battery is so implemented that it can get regeneratively charged when primary power supply is capable of handling an additional load, i.e. the battery. The charging and discharging of the battery is carried out in closed loop mode to ensure constant battery terminal voltage, constant battery current and constant load voltage as per the requirement. A novel sliding mode controller is used to improve transient and steady-state response of the system.

A systems perspective of waste management allows an integrated approach not only to the five basic functional elements of waste management itself (generation, reduction, collection, recycling, disposal), but to the problems arising at the interfaces with the management of energy, nature conservation, environmental protection, economic factors like unemployment and productivity, etc. This monograph separately describes present practices and the problems to be solved in each of the functional areas of waste management and at the important interfaces. Strategies for more efficient control are then proposed from a systems perspective. Systematic and objective means of solving problems become possible leading to optimal management and a positive contribution to economic development, not least through resource conservation. India is the particular context within which waste generation and management are discussed. In considering waste disposal techniques, special attention is given to sewage and radioactive wastes.

This study empirically aims to examine the relation between CEO power and firm engagement in corporate social responsibility (CSR). It undertakes an in-depth analysis of how the structural, ownership and expert dimensions of CEO power affect individual dimensions of CSR.

This study uses ordinary least squares and industry fixed-effects regressions. It also uses instrumental variable-generalized method of moment regressions to test the robustness of empirical results.

Results indicate that CEO power is negatively related to CSR. However, the relation between CEO power and CSR is influenced by CSR strengths, as power is negatively related to CSR strengths and is not related to CSR concerns. Results also indicate that the structural and ownership dimensions of CEO power are negatively related to CSR, and the expert dimension has no significant effect on CSR. Moreover, results show that CEO power is not related to the product dimension of CSR performance.

CEO power is measured using the structural, ownership and expert dimensions of power. However, CEOs also acquire power through social networks and connections outside the corporation which is not covered in this study.

This study uses comprehensive measures of CEO power and CSR. It is the first study that examines the effect of dimensions of CEO power on individual dimensions of CSR performance.

The purpose of this paper is to provide a theoretically informed analysis of a struggle for power over the regulation of corporate social responsibility (CSR) and social and environmental accounting and reporting (SEAR) within the European Union.

The paper combines insights from institutional theory (Lawrence and Buchanan, 2017) with Vaara et al.’s (2006) and Vaara and Tienar’s (2008) discursive strategies approach in order to interrogate the dynamics of the institutional “arena” that emerged in 2001, following the European Commission’s publication of a Green Paper (GP) on CSR policy and reporting. Drawing on multiple sources of data (including newspaper coverage, semi-structured interviews and written submissions by companies and NGOs), the authors analyse the institutional political strategies employed by companies and NGOs – two of the key stakeholder groupings who sought to influence the dynamics and outcome of the European initiative.

The results show that the 2001 GP was a “triggering event” (Hoffman, 1999) that led to the formation of the institutional arena that centred on whether CSR policy and reporting should be voluntary or mandatory. The findings highlight how two separate, but related forms of power (systemic and episodic power) were exercised much more effectively by companies compared to NGOs. The analysis of the power initiatives and discursive strategies deployed in the arena provides a theoretically informed understanding of the ways in which companies acted in concert to reach their objective of maintaining CSR and SEAR as a voluntary activity.

The theoretical framework outlined in the paper highlights how the analysis of CSR and SEAR regulation can be enriched by examining the deployment of episodic and systemic power by relevant actors.

This paper aims to provide a permanent magnet synchronous generator (PMSG) wind turbine, which feeds electric power (AC) to the power grid. The converter, located on the machine side, is used to produce the full amount of wind power. Research on wind energy conversion system (WECS) is carried out in this study using a direct wind turbine in MATLAB with constant and variable speeds.

This paper is about WECS using PMSG and is connected to a grid of two serial converters with common DC connections.

This paper aims to provide the value of DC connection voltage at its base, regardless of the wind speed alterations, the inverter's output ac voltage can be kept constant.

This paper aims to provide a Hill Climb Search maximum power point tracking (MPPT) algorithm is an effective control system for extracting maximum energy, also called voltage control, pitch control, phase-locked loop (PLL) controls, from a wind turbine. Using the Fuzzy controller, the grid side converter is controlled.

Attempts to transfer Western management theories without considering the host's cultural value system is a prescription for failure. While conceptual frameworks for understanding cultural differences exist, such as the ones developed by Hofstede and Hall, we know little about which managerial practices are relevant in what cultural settings. Adopting the view that the effectiveness of different management behaviors depends on the culture in which they are practiced, this paper develops various propositions that match specific managerial behaviors with cultural work values. The matching of managerial behaviors with cultural values has a wide range of applications in overseas selection decisions and training programs.

Direct energy deposition (DED) is an additive manufacturing process that allows to produce metal parts with complex shapes. DED process depends on several parameters, including laser power, deposition rate and powder feeding rate. It is important to control the manufacturing process to study the influence of the operating parameters on the final characteristics of these parts and to optimize them. Computational modeling helps engineers to address these challenges. This paper aims to establish a framework for the development, verification and application of meshless methods and surrogate models to the DED process.

Finite pointset method (FPM) is used to solve conservation equations involved in the DED process. A surrogate model is then established for the DED process using design of experiments with powder feeding rate, laser power and scanning speed as input parameters. The surrogate model is constructed using neutral networks (NN) approximations for the prediction of maximum temperature, clad angle and dilution.

The simulations of thin wall built of Ti-6Al-4V titanium alloy clearly demonstrated that FPM simulation is successful in predicting temperature distribution for different process conditions and compare favorably with experimental results from the literature. A methodology has been developed for obtaining a surrogate model for DED process.

This methodology shows how to achieve realistic simulations of DED process and how to construct a surrogate model for further use in optimization loop.

This paper proposes an anthropology‐based theoretical model describing the impact of top management culture clash on the commitment of the acquired team to the new organization and on its cooperation with the acquiring team. It suggests that three factors are influential, namely the degree of cultural differences, the nature of the contact between the teams, and the intended level of integration between the companies. The paper generates numerous propositions for predicting the impact of the culture clash. It also offers suggestions for further theoretical and empirical study, and presents some of the model's practical implications.

Agency theoretic models have been used in the past to justify the use of stock options as an effective incentive alignment mechanism to create a common fate between principals and agents. In this paper, we use behavioral theory to reach the opposite conclusion – namely, that the design characteristics of the typical stock option plan foster perverse incentives for loss‐averse agents, leading to decisions with detrimental consequences for principals. We also consider alternative stock option designs and other equity‐based executive compensation plans and argue that they may suffer from the same problems as traditional stock option plans – namely, that loss‐averse executives will try to protect the endowed value of that equity through self‐serving decisions that do not enhance shareholder wealth.